JP2002013088A - Felt for papermaking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a felt for papermaking capable of maintaining a three- dimensional structure against a pressure continuously received by a high-speed paper machine and keeping draining performances from an early period of use. SOLUTION: In this felt for papermaking obtained by laminating a fiber web 3 to one side or both sides of a base fabric layer 2 composed of a woven fabric and interlacing and integrating the laminate by needling, the felt is characterized in that the whole yarns of warps 2a and wefts 2b constituting the base fabric layer 2 or a part of uniformly dispersed yarns of the warps 2 or the wefts 2b is replaced with straight yarns S, respectively. The warps or the wefts themselves constituting the base fabric layer 2 exhibit high dimensional stability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a papermaking felt used in a water-squeezing step in a paper mill, which can reduce a dimensional change in the MD and CMD directions during use. It is about.

[0002]

2. Description of the Related Art Papermaking felts conventionally used in the water-squeezing process of paper mills are required to efficiently squeeze water from wet paper. It is important that the water squeezing performance be maintained from the beginning of use. Because the felt for papermaking is repeatedly pressed during the orbiting in the papermaking machine, the water squeezing performance gradually deteriorates, and it is time to replace it with a new one over time. This is because it is necessary to maintain the water squeezing performance.

In addition, felts for papermaking are required to maintain high running stability. That is, the felt for papermaking passes through the press section for squeezing out the moisture from the wet paper web and the press section of the continuous washing apparatus. This is because it is necessary to maintain the three-dimensional structure of the papermaking felt by the resilience and ensure water permeability.

[0004]

However, in recent high-speed paper machines, the time from the passage of the first press section to the passage of the next press section is short (about 1 second), and the nip in the press section is further reduced. Because the pressure is high,
Insufficient time has been given to expect the elastic recovery force for maintaining the three-dimensional structure of the papermaking felt. In addition, repetition of this state causes a change in dimensions, and in a place where the normal life is about 40 days, in a short time (several days), running instability such as the end of use or poor water squeezing occurs. There were various problems.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a felt for papermaking which can maintain a three-dimensional structure even when subjected to continuous compression in a short time by a high-speed papermaking machine. I have.

[0006]

In order to achieve the above-mentioned object, the present invention provides a method for fabricating a woven fabric, comprising:
In a papermaking felt obtained by laminating fiber webs and entangled and integrated by needling, the whole warp or weft constituting the base fabric layer, or a part of the warp or weft uniformly dispersed yarns is used. Each of them is characterized by being replaced with a straight yarn, so that the warp or the weft itself constituting the base fabric layer can maintain high dimensional stability.

The invention according to claim 2 is a papermaking felt obtained by laminating a fiber web on one or both sides of a base fabric layer made of a woven fabric and entangled and integrated by needling. The layer is composed of bent yarns, characterized in that it is evenly distributed along the warp or weft and straight yarns are additionally inserted. It was configured to maintain stability.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic enlarged cross-sectional view of a felt of the present invention in which a double woven fabric is used as a base fabric layer, and a part of the warp or weft is made into a straight yarn. FIG. Using a woven fabric, a schematic enlarged cross-sectional view of the felt of the present application in which a part of the warp or the weft is a straight yarn,
FIG. 3 is a schematic enlarged sectional view of the felt of the present application in which a straight yarn is added to a warp or a weft of a base fabric layer.

The felt 1 of the present application is obtained by laminating fiber webs 3 and 3 on both upper and lower surfaces (or one surface) of a base fabric layer 2 made of a woven fabric, and by needling (remaining as a needling trace but not shown). It becomes entangled and integrated.

The base fabric layer 2 has a dimensional stability by using the straight yarn S in order to maintain the three-dimensional structure and to maintain the water squeezing performance. There are two ways to use the straight yarn S. One is shown in FIGS. 1 (a), (b) and FIG.
As shown in (a) and (b), a part of the warp yarn 2a or the weft yarn 2b (or either the whole warp yarn 2a or the whole weft yarn 2b) of the warp yarn 2a or the weft yarn 2b constituting the base fabric layer 2 is converted into the straight yarn S. The yarn is replaced and the other yarn remains the bent yarn K. The other one is as shown in FIGS. 3A and 3B.
Is composed of a bent yarn K, and the straight yarn S is additionally inserted evenly distributed along the warp yarn 2a or the weft yarn 2b.

The straight yarn S is "evenly dispersed".
This means that every other bent yarn K is arranged (1: 1), every other bent yarn K is arranged (1: 2), or every other bent yarn K is arranged. The case of this arrangement (2: 1) is assumed. However, the composition ratio of the straight yarn S to the bent yarn K is preferably 40% or more in order to enhance the three-dimensional structure of the base fabric layer 2.

In the case where the straight yarn S is additionally inserted, the straight yarn S is arranged along the warp yarn 2a or the weft yarn 2b inside the base fabric layer 2 composed of the bent yarn K in FIGS. 3 (a) and 3 (b). However, the sheet-like material in which the straight yarns S are arranged is arranged by heat bonding (laminating) or adhesive bonding with a certain direction on the outer surface of the base fabric layer 2 composed of the bent yarns K. In some cases.

In the drawings, ◎ indicates a straight yarn on the warp side, ○ indicates a bent yarn on the warp side, a double line indicates a straight yarn on the weft side, and a double line with a dotted pattern indicates a straight line on the weft side. Each of the bent yarns is shown.

In each of the base fabric layers 2 shown in FIGS. 1 to 3, straight yarns S exist in both the warp direction and the weft direction. Therefore, it is formed so as to achieve dimensional stability in all directions in the MD and CMD directions during use.
It is needless to say that the same dimensional stability can be attained only by the presence of. For example, when the straight yarn S is inserted in the weft direction of the base fabric layer 2, the modulus in the weft direction increases,
The width change (with width) during heat setting in the manufacturing process is small, and the width of the felt 1 of the present application when the product is used on a paper machine as a product, and the decrease in thickness is also reduced, and the width is also reduced. This is because the traveling stable structure is hard to extend.

In the case where the base fabric layer 2 is formed in a weft double or triple weave (multiple), the straight yarn S is formed in the warp direction, and the base fabric layer 2 is formed in a warp double or warp triple weave. It has been confirmed that, when the straight yarn S is inserted in the weft direction, a stable structure with little dimensional change during use is obtained for both the longitudinal and weft directions. In particular, it can contribute to improvement of dimensional stability during use as a felt for papermaking used in recent high-speed papermaking machines.

The straight yarn S is, of course, a yarn having straightness, for example, a PET (polyethylene terephthalate) monofilament, but not only this, but also a comparison (relative) with the bent yarn K. Including those determined in. For example, the bending yarn K
When using a relatively stretchable flexible yarn such as nylon, a relatively inflexible yarn such as PBT,
Monofilaments such as PPS, Ny610, Ny612, Ny12, semi-aromatic nylon (MXD6) and aramid, or multifilaments may be used as straight yarns. Of course, straight yarns are not always used as straight-arranged yarns, but may be arranged close to straight at the time of weaving. Needless to say, such straight yarns are also included.

In the case shown in FIGS. 1 (a) and 1 (b) and FIGS. 2 (a) and 2 (b), the bent yarn K is used to anchor the straight yarn S (to float and sink with respect to the straight yarn S). 3 (a) and 3 (b). In the case shown in FIGS. 3 (a) and 3 (b), it refers to a yarn which forms a ground structure.

[0018]

As described above, the present invention relates to a papermaking felt obtained by laminating a fiber web on one or both sides of a woven fabric base layer and entangled and integrated by needling. It is characterized by replacing all the warp or weft yarns, or a part of the warp or weft evenly dispersed yarns, with straight yarns, respectively.
Due to the dimensional stability of the warp or weft of the base fabric layer using the straight yarn, the modulus in the insertion direction of the straight yarn increases, and therefore, the width change (including width) during heat setting in the manufacturing process is reduced, and papermaking is performed. It has a stable running structure that hardly extends in the longitudinal and width directions due to a decrease in width and thickness when used on a machine, and can satisfy the performance as a felt for papermaking over a long period of time. It is effective.

The invention according to claim 2 is a papermaking felt obtained by laminating a fiber web on one or both sides of a base fabric layer made of a woven fabric and entangled and integrated by needling. The layer is composed of bent yarns, and it is characterized by the fact that the straight yarn is additionally inserted by uniformly dispersing along the warp or weft, so that the ground structure of the base fabric layer is reinforced with straight yarns, This is an excellent effect that high dimensional stability of the base fabric layer can be easily obtained.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic enlarged cross-sectional view of a felt of the present application, in which (a) uses a double-woven woven fabric for a base fabric layer and straightens some of the warp or weft yarns, (b) Is the case where the structure of the base fabric layer was changed.

FIG. 2 is a schematic enlarged cross-sectional view of the felt of the present application, in which (a) uses a multi-woven woven fabric for a base fabric layer and straightens some of the warp or weft yarns, and (b) shows This is a case where the structure of the base fabric layer is changed.

FIG. 3 is a schematic enlarged cross-sectional view of a felt of the present application, in which (a) is a warp or weft of a base fabric layer with a straight yarn added thereto,
(B) shows a case where the structure of the base fabric layer is changed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Felt of this application 2 Base fabric layer 2a Warp 2b Weft 3 Fiber web S Straight yarn K Bending yarn

Claims (2)

[Claims] Claims: 1. On one or both sides of a woven fabric base layer,
In a papermaking felt obtained by laminating fiber webs and entangled and integrated by needling, the whole warp or weft constituting the base fabric layer, or a part of the warp or weft uniformly dispersed yarns is used. Felt for paper making characterized by replacing each with a straight yarn. 2. One or both sides of a base fabric layer made of a woven fabric,
In a papermaking felt obtained by laminating fiber webs and entangled and integrated by needling, the base fabric layer is composed of bent yarns, and the straight yarns are additionally inserted evenly along the warp or weft. A felt for papermaking, characterized in that: